Defines starting with `t' in 321/game

• TAG_GAME 321/game/g_local.h:76
• TAG_LEVEL 321/game/g_local.h:77
• TRAIL_LENGTH 321/game/p_trail.c:39
• TRAIN_BLOCK_STOPS 321/game/g_func.c:1447
• TRAIN_START_ON 321/game/g_func.c:1445
• TRAIN_TOGGLE 321/game/g_func.c:1446